# US 2021/0380484 A1 · Boron-free anti-sagging additive for gypsum building materials

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- Number: US 2021/0380484 A1
- Document ID: US20210380484A1
- Status: Published application
- Kind: A1
- Application number: 17/287,011
- Filed: 2018-10-26
- Published: 2021-12-09
- Earliest claimed: 2018-10-26
- Assignees: Knauf Gips KG
- Applicants: Knauf Gips KG
- Inventors: Bernd PIETSCHMANN; Michael STEINBAUER; David WEIGAND; Verena KOHLER; Juliane KÖHLER
- Web page: https://patentgrep.com/patent/US20210380484A1

## CPC

- C04B 28/14: containing calcium sulfate cements {(gypsum-paper plates E04C)}
- C04B 40/0039: {Premixtures of ingredients}
- C04B 7/02: Portland cement
- C04B 24/06: containing hydroxy groups
- C04B 2103/0082: {Segregation-preventing agents; Sedimentation-preventing agents}
- C04B 2103/0094: {Agents for altering or buffering the pH; Ingredients characterised by their pH}
- C04B 2111/00094: {Sag-resistant materials}
- C04B 2111/0062: {Gypsum-paper board like materials}
- C04B 2111/10: Compositions or ingredients thereof characterised by the absence or the very low content of a specific material
- C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE

## Abstract

The invention concerns an anti-sagging additive for producing shaped gypsum articles. The additive is boron-free and comprises L-tartaric acid and/or L-tartrates and a pH-enhancing compound.

## Claims

### Claim 1

An anti-sagging additive for producing shaped gypsum articles, comprising L-tartaric acid and/or L-tartrates and a pH-enhancing compound but no boron-containing compounds.

### Claim 2 (depends on 1)

The anti-sagging additive according to claim 1, wherein the pH-enhancing compound is a cement.

### Claim 3 (depends on 1)

The anti-sagging additive according to claim 1, wherein a ratio of an amount of L-tartaric acid or L-tartrate to an amount of pH-enhancing compound is from 1:1 to 1:10.

### Claim at position 4

4-5. (canceled)

### Claim 6

A shaped gypsum article produced at least from a slurry formed from calcined gypsum, water, and an anti-sagging additive, wherein the anti-sagging additive comprises L-tartaric acid and/or L-tartrates and a pH-enhancing compound but no boron compounds.

### Claim 7

A method for producing a shaped gypsum articles comprising steps of mixing of calcined gypsum with water and an additive, wherein the additive comprises L-tartaric acid and/or L-tartrates and a pH-enhancing compound, and forming the shaped gypsum article.

### Claim 8 (depends on 3)

The anti-sagging additive according to claim 3, wherein the ratio of the amount of the L-tartaric acid or the L-tartrate to the amount of the pH-enhancing compound is from 1:2 to 1:5.

### Claim 9 (depends on 6)

The shaped gypsum article according to claim 6, wherein the L-tartaric acid and/or the L-tartrates is/are contained in a mass of from 0.001 to 0.1% by weight in relation to a mass of the calcined gypsum.

### Claim 10 (depends on 9)

The shaped gypsum article according to claim 9, wherein the L-tartaric acid and/or the L-tartrates is/are contained in the mass of from 0.01 to 0.05% by weight in relation to the mass of the calcined gypsum.

### Claim 11 (depends on 6)

The shaped gypsum article according to claim 6, wherein the pH-enhancing compound is contained in a quantity of from 0.05 to 0.5% by weight in relation to a mass of the calcined gypsum.

### Claim 12 (depends on 11)

The shaped gypsum article according to claim 11, wherein the pH-enhancing compound is contained in the quantity of from 0.08 to 0.25% by weight in relation to the mass of the calcined gypsum.

### Claim 13 (depends on 6)

The shaped gypsum article according to claim 6, wherein the shaped gypsum article is a gypsum board.

### Claim 14 (depends on 7)

The method according to claim 7, wherein the shaped gypsum article is a gypsum board.

### Claim 15 (depends on 7)

The method according to claim 7, wherein the method comprises the step of drying the shaped gypsum article.